Detection of heavy ions using Nb-based superconducting tunnel junction

Author

Sato, Hiromi ; Ikeda, Tokihiro ; Kawai, Kazuhiko ; Miyasaka, Hiromasa ; Oku, Takayuki ; Ootani, Wataru ; Otani, Chiko ; Shimizu, Hirohiko M. ; Takizawa, Yoshiyuki ; Watanabe, Hiroshi ; Morimoto, Koji ; Tokanai, Fuyuki ; Akoh, Hiroshi ; Nakagawa, Hiroshi ;

Author_Institution

RIKEN, Inst. of Phys. & Chem. Res., Saitama, Japan

Volume

11

Issue

1

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

712

Lastpage

715

Abstract

The superconducting tunnel junction (STJ) is one of the most promising devices to use as a fast detector for heavy ions. The energy deposited due to the passage of a heavy ion through an STJ forms a region called a hot spot, where the superconductivity of the region is broken. As a result, a reduction of the critical current (I_c) in the STJ occurs. If the bias current exceeds this reduced I_c, the output voltage from the STJ switches from 0 V to its gap voltage, which is recognizable as a signal due to the heavy ion passage. Nb-based STJs were fabricated for this heavy ion detector and an experiment was performed at the RIKEN Ring Cyclotron Facility to investigate the response to heavy ions. Instantaneous switching to the voltage state of the STJ in response to the decrease in I_c induced by a heavy ion beam was successfully observed by introducing ⁴⁰Ar particles with a kinetic energy of 95 MeV/nucleon into the STJ

Keywords

critical currents; niobium; superconducting junction devices; superconducting particle detectors; superconductive tunnelling; Ar; Nb; critical current; energy deposition; heavy ion detection; hot spot; superconducting tunnel junction; voltage switching; Argon; Critical current; Cyclotrons; Detectors; Ion beams; Josephson junctions; Kinetic energy; Superconductivity; Switches; Voltage;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.919444

Filename

919444